Self-sharpening dipper tooth



May 4, 1932- J. c. 'ILAYLOR, JR

Filed Aug. 27, 1931 "MINI Patented May 24, 1932 UNITED STATES. PATENT OFFICE JOHN C. TAYLOR, JR, OF EASTON, PENNSYLVANIA, ASSIGNOR TO TAYLORYWHABTON IRON AND STEEL COMPANY, OF HIGH BRIDGE, NEW JERSEY, A CORPORATION OF NEW JERSEY SELF-SHARPENING DIP-PER TOOTH Application filed August 27, 1931,, Serial No. 559381;?

Digging teeth or so-called dipper teeth sufler more or less rapid wear in service and for economical reasons it has been standard practice for many years to make the polnt separate from the base so that it can be re- I have a sllght groove or indentation 8 which versed after one side is badly worn and so that it can be re laced eventually when it has outlived its use ulness. The point being of wedge form, the effect of wear is to mcrease 10 its digging section so that, notwithstandlng reversal from time to time, it becomes too blunt for effective digging and consequently, must be replaced.

The object of my invention is to prolong the useful life of points of dipper teeth bfy constructing them so that they Wlll be sel sharpening and will always present an effective digging edge notwithstand ng progressive increment of section.

The nature of the invention conslsts in so constructing the point as to provide a potential area of division, as by indentation, grooving, recessing, or channeling, medially of the cutting edge and which becomes more and more defined with progressive increase of point section thereby to overcome the ordinary condition of bluntness of section y establishing twin or multiple cutting points, as, for example, by constructing a point with a cored area extending from its apex rearwardly to or near the region of the web or shank, for the purpose and with the result of providing for self-sharpening of the point in service.

One embodiment of the invention is shown in the accompanying drawings forming a part hereof, wherein Figure 1 is a perspective view of a point having self-sharpening capacity in accordance with my invention.

Fig. 2 is a central longitudinal sectional View of the same.

Fig. 3 is a section on line 3-3 of Fig. 2.

Fig. 4 is a perspective View illustrative of a tooth which has sharpened itself in service.

Except as hereinafter noted the dipper tooth both as regards point and base, is or may be as usual. According to my invention the point 5 is constructed, either in the act of casting or otherwise, with a medial cored area 6 extending from its apex rearwardly to, or in the region of the Web or shank'l, for the purpose and with the result of providing for self-sharpening of the oint in service.

A point of this type, efore service, would ii ould become more and more defined with incifiease of point section so as to result in the cdpdition shown in Fig. 4, which represents how, n-ot\\"ithstanding, increment of digging section, the indenting, grooving, or division of the cutting edge becomes more pronounced as the wear makes for larger section. The described self-sharpening action of the new tooth results in the establishment of twin cutting edges 9.

Whether the section of the cored area be circular, polygonal or a compromise thereof, is of no particular importance although it is perhaps easier to use the circular cross section shown in the drawings. In any event, I prefer to increase'the cross-sectional area in a direction rearwardly of the point, that is to say,-in conformity with increase of digging section. The effect of this is to accentuate the line of parting of the digging edge or, in short, to promote the self-sharpening capacity of the point. And as before intimated,

the cored area may extend from or immediately back of the apex of the point to or within the region of the web or shank. So far as concerns the principle of self-sharpening it would be sufficient to have the cored area stop short of the rear wall of the point. On the other hand by having it extend to the clear there might be some advantage in the heat treatment of points of relatively large sectlon.

Having described my invention, I claim 1. A digging tooth having a point formed internally with a recess ranging rearwardly of its cutting edge, whereby the cutting edge is divided in response to wear to overcome bluntness.

2. A digging tooth having a point formed with an axial recess effective to establish multiple digging edges in response to wear.

3. A digging tooth having a point formed with a recess that opens into the cutting edge to overcome bluntness in response to wear.

4. A digging tooth having a oint whereof the cutting edge is formed wit an mdentation and whereof the bod ,has acored portion coextensive with sai indentation.

5. A digging tooth having a oint, the cutting edge of which is groove or indented, the bac wall of the groove having a recess extending longitudina 1y into the body.

6. A dlgging tooth havin a point of conventional wedge form, and an axial cored portion in the path of wear and efiective to establish apical rugosities in response to wear.

7 A digging tooth having a point of conventional wedge form with a cored portion ranging axially thereof, whose cross sectional area increases in conformity with increase of digging section.

8. A selfharpening digging tooth having a point of conventional wedge form whereof the cutting edge is grooved, the back wall of the groove having a tubular opening extending the effective length of the point.

9. Adigging tooth of the solid wedge form having a central cavity substantially the depth thereof and effective to divide the point to overcome the usual bluntness following wear.

In testimony whereof, I affix my signature.

JOHN C. TAYLOR, JR. 

